Two long, straight, parallel conductors are mounted apart. Both carry equal currents…
PHYSICS · Single correct · AP · Physics C: Electricity and Magnetism · Magnetic Fields and Electromagnetism · Magnetic Fields and Electromagnetism
Problem
Two long, straight, parallel conductors are mounted 0.20m apart. Both carry equal currents of 6A. Which of the following statements best explains why the conductors experience an attractive force?
(a) According to Lenz’s law, the current in one conductor induces an opposite current in the other, and opposite currents attract, so the wires are pulled together.
(b) Between the two conductors the magnetic fields cancel, creating a region of lower magnetic pressure that draws the wires toward each other.
(c) Each current produces a magnetic field that threads the other wire; the field from one wire exerts a magnetic force IℓB on the moving charges in the second that is directed toward the first, so the wires attract.
(d) The moving charges in each wire induce opposite electrostatic charges on the facing surfaces, and those opposite charges attract, pulling the wires together.